As I reported last week, the BlackBerry Curve 8910 is indeed real - in fact, it's taking a little walk through the FCC's headquarters at present. Considering the lack of 3G and the fact that it falls in the 89XX family, my guess is that RIM is continuing the migration from trackball to trackpad, and is simply upgrading the Curve 8900 series with a slightly modified look, a trackpad, and OS 5.0 out of the box. I would expect AT&T and T-Mobile to pick this up in the coming months as a replacement to the Curve 8900.
Does it matter? Is the update worthwhile, given the lack of 3G connectivity?